PORTLAND — Lamenting that the “sensible center has now virtually disappeared,” U.S. Sen. Olympia Snowe on Friday renewed her call for consensus building in the polarized Senate. She said voters need to reward instead of punish lawmakers willing to set aside partisanship to find common ground.

Snowe, R-Maine, also had a rebuke for those at the extremes of both parties who criticize centrists like Snowe who’re willing to compromise.

“There are people who condemn moderation. They say it’s a capitulation of principles. It is not. You have your principles and then you decide how to reach the end goal to achieve those principles,” Snowe said to a roar of applause from a roomful of Republicans at a hotel next to the Portland International Jetport.

Looking relaxed, Snowe met with reporters and supporters in Maine for the first time since she shocked the political establishment with her decision not to seek a fourth term, bringing to an end a congressional career that has spanned more than three decades.

Republicans gave her a standing ovation when she entered the room, prompting a quip from Snowe: “You’d think I’m running for something.”

With her husband, former Gov. John McKernan, and her self-described “large Greek family” behind her for support, she said she’d contemplated the decision for some time but that her 65th birthday less than two weeks ago provided a “clarifying moment.”

She said the Senate is supposed to be a place for civility and consensus building, and that instead it’s evolved into something closer to a parliamentary system where politicians stick with their respective ideologies and get little accomplished.

Snowe said she doesn’t see the corrosive politics getting better anytime soon. That’s why she decided to leave after her third term ends.

Her decision gives Democrats a shot at winning a seat Republicans were expected to keep easily, and left potential candidates hoping to fill the seat with two weeks to collect signatures to qualify for the June ballot.

She said she remains hopeful for change in which Republican and Democrats alike work together when their own proposals fail.

“In a politically diverse nation, it’s only through finding common ground that we achieve results for the common good. The only way this will happen is when our leaders realize that there’s a time for campaigning and there is a time for governing, where they understand that there’s not only strength in compromise, that there’s honor in consensus building and courage in conciliation,” she said.

Snowe, who was described as the most liberal Republican in the Senate, made no apologies for her political views or for reaching across the aisle. “I’ve been this way as a moderate since I came to the U.S. House in 1978, so I’ve known no other way,” she said.

Maine Senate President Kevin Raye, who worked on Snowe’s first congressional campaign when he was too young to vote and later served as her chief of staff, said it’s wonderful to her “going out on top” but said her reason for leaving is distressing.

“Olympia’s departure has in many ways awakened in people the degree of dysfunction and how damaging that is to the country. In many ways it’s a clarion call,” he said.

Looking to the future, Snowe said she decided she’d be in a better place to help change the polarized atmosphere by working outside the Senate. She said she hadn’t come with any conclusions about how she’ll fulfill that role.

She also brushed off a question about getting involved with a third party, saying the onus is the major parties to restore civility and effectiveness in Washington.

Snowe reiterated that she’s in good health and enjoyed plenty of support and expected to win re-election. She said she’s even picked up some support from tea party activists during the many meetings she’s held across the state.

McKernan said a federal lawsuit against the for-profit college corporation on which he serves as board chairman was a nonissue when it came to Snowe’s decision. Pittsburgh-based Education Management Corp. is in compliance with federal rules and a motion to dismiss the year-old lawsuit is pending, he said.

All told, Snowe spent 33 years in Congress. She said it was an honor and a privilege to serve, proclaiming that what got her up each morning was “the promise of producing results and getting things done for the people who have entrusted me to be their megaphone, their advocate, their voice and their vote.”

“Whether you have agreed or disagreed with me on the issues over the years, please know that I’ve given my heart and soul to the solemn obligation that I have felt each and every day that I have served in my office,” she said. “These are the moments I will cherish. And for each and every moment, I thank you.”